Mold



l 1,449,789. R. D. SMITH. l

MOLD.

ED Nov.17. 1921.

Mar. 27, 1923.

1NvENToR v BY` ATToRNE Rowland QSmt-,

M i W 30 fabricated, which will Patented Mar. 27, 1923.

NITED STATES PATENT FFICE.

ROWLAND D. SMITH, OF CORNING, NEW YORK, ASSIGNOR T CORNING GLASS WORKS,

0F CORNING, NEW YORK, A CORPORATION OF NEW YORK.

MOLD.

Application led November 17, 1921. Serial No. 515,892.

To all whom t may concern.'

Be it known that I, ROWLAND D. SMITH, a citizen of the United States of America, anda resident of Corning, New York, have f invented certain new and useful Improvements in Molds, specification.

One of the most frequent causes of the destruction of molds or molding parts (including plungers, valves, etc.) used in the manufact-ure of glassware, is the checkin or cracking of the surface of such parts. his is particularly marked, when in such parts, are Aused glasses that require to be pressed e at a comparatively high temperature. With `a certa-in glass with which I have worked, the amount of deterioration from this cause is shown by the fact that a chilled gray cast iron mold part failed bycheckin and had to be discarded after sixty hours o service, while an unchilled gray cast iron mold part failed from the same cause after a 120 hours service.

Inasmuch as these mold parts have to be accurately formed, finishedl and polished,

this early failure renders'the cost of articles produced'by such parts excessive, and this invention has for its object to provide a material from which such parts should be give a much longer life; i I have found that chromium cobalt, chromium silicon, or chromium steels, are especially suitable for the purpose had in mind,

and the following are the compositions of of which the following is a sin and to that extent three steels falling within this invention A B C Chromium 13.6% 10 to 15% 8 to 13% Coba1t 2 to 5% Carbon .8 to 1.5% .5% Manganese .5% 0

olybdenum 1% con 4 Iron 86.5% 83% 84% The'steels of A and C are forging steels,

are difficult to work. They, however, give about twenty times the l4.5 length of service of chilled iron. Composition B is capable of being'cast, and to that extent is more desirable for certain purposes than compositions A or C.

I have in the accompanying drawing 5o shown a valve such as used in glass molds embodying this invention, and which can be made from either ol the compositions above given. v

Having thus described my invention what I claim as new and desire to secure by Leto ters Patent is A v 1. Apart for molding glassware madeof a steel containing from 10 to 15% chromium, and from 5% to 5% cobalt.

2. A part for moldingglassware made of steel containing about 13% chromium, about 70 manganese, about 6/10ths% cobalt, and of about' .35% of carbon.

3. A part for molding glassware made of 65 steel containing chromium and about 4% silicon. l

, In testimony whereof I hereunto sign my name this 16th day of November 1921.

ROWLAND D. SMITH. 

